Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Describe why the bile acids are much better suited, All of the following il...

All of the following illustrate why the bile acids are much better suited then cholesterol for use as emulsification agents for fats except: -cholesterol contains a hydroxyl gro

Which is the normal sign of the electric charge, Which is the normal sign o...

Which is the normal sign of the electric charge among the two sides of the neuron plasma membrane? What is the potential difference (voltage) generated among these two sides? What

Explain about single cell proteins, Single Cell Proteins (SCP)  The t...

Single Cell Proteins (SCP)  The term SCP was coined by Prof. Caroll Wilson (MIT) in 1966. It means the proteins obtained from microbial sources, i.e. algae, fungi, bacteria,

Illustrate the thin and think filaments in the muscle fiber, Illustrate the...

Illustrate the thin and think filaments in the muscle fiber A healthy skeletal muscle fiber is isolated and has no external forces on it.  It has normal intracellular levels of

What is plant coleoptile, What is plant coleoptile? Why does the removal of...

What is plant coleoptile? Why does the removal of the coleoptile extremity disallow plant growth? Coleoptile is first (one or more) aerial structure of the sprouting plant that

Interspecific competition, Darwin while evolving the concept of natural sel...

Darwin while evolving the concept of natural selection laid emphasis on competition among individuals belonging to a species, that is intraspecific competition. Here the individual

How vitamin e provide synthesis of enzymes and proteins, How Vitamin E prov...

How Vitamin E provide Synthesis of enzymes and proteins? 1) Synthesis of enzymes and proteins: It serves as a co-repressor in the synthesis of certain enzymes and plays a speci

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd